This invention relates to reducing machines.
Coal as it is taken from the mine is for the most part too large for commercial purposes. In order to bring the mine coal to a commercially acceptable size, the coal is usually run through a coal crusher which normally reduces it to pieces no larger than 3/4 to 1 inch in size. However, some of the coal from the mine is already in the 3/4 to 1 inch size range and when this coal passes through a crusher, much of it changes to fines which is undesirable. Also, passing the properly sized coal through the crusher reduces the capacity of the crusher and consumes excessive power.
Aside from the foregoing, some of the coal introduced into any crushing machine is merely carried around by the rotor, even though it is small enough to pass through the openings in the screen beneath the rotor. This coal tends to be propelled toward the breaker plates at the inlet of the machine, and then passes over the screen again where it is reduced still further. The end result is likewise an increase in fines and a reduction in the overall capacity of the crusher.